Results Seen in Small Study's Before-and-After Organic Diet Makeover

The effect was "dramatic and immediate," write Chensheng "Alex" Lu, PhD, MS, and colleagues. Lu is an assistant professor in the environmental and occupational health department of Emory University's Rollins School of Public Health in Atlanta.

Lu's team studied malathion and chlorpyrifos, two pesticides commonly used in conventional agricultural production. Organic foods aren't treated with any synthetic pesticides. Pesticides derived from natural sources (e.g. biological pesticides) may be used in producing organically grown food, says the EPA.

The study, which was funded by the U.S. Environmental Protection Agency (EPA), recently appeared in the online edition of Environmental Health Perspectives.

Strict Standards for Safety

Pesticides are strong chemicals. According to the EPA web site, "By their very nature, most pesticides create some risk of harm. Pesticides can cause harm to humans, animals, or the environment because they are designed to kill or otherwise adversely affect living organisms. At the same time, pesticides are useful to society. Pesticides can kill potential disease-causing organisms and control insects, weeds, and other pests."

Direct exposure to the type of pesticides studied by Lu can overstimulate the nervous system, causing nausea, dizziness, and confusion. Very high exposures (such as accidents or major spills), can paralyze breathing or even be fatal, states the EPA's web site.

But foods treated with malathion and chlorpyrifos are safe to eat, according to the EPA.

The EPA has strict rules about pesticide use. Limits include the amount of pesticides that can be used in growing and processing foods and the amount of pesticide residue on foods people buy.

"Most importantly, each of these decisions must protect infants and children, whose developing bodies may be especially sensitive to pesticide exposure," states the EPA's web site.

According to the EPA web site, children are at a greater risk for some pesticides for a number of reasons. Children's internal organs are still developing and maturing, and their enzymatic, metabolic, and immune systems may provide less natural protection than those of an adult. There are "critical periods" in human development when exposure to a toxin can permanently alter the way an individual's biological system operates. Children may be exposed more to certain pesticides because often they eat different foods than adults.

For instance, children typically consume larger quantities of milk, applesauce, and orange juice per pound of body weight than do adults. Children's behaviors, such as playing on the floor or on the lawn where pesticides are commonly applied, or putting objects in their mouths, increase their chances of exposure to pesticides.